Removal Treatment Research Articles

Effects of Post-Processing Parameters on 3D-Printed Dental Appliances: A Review.

In recent years, additive manufacturing (AM) has been recognized as a transformative force in the dental industry, with the ability to address escalating demand, expedite production timelines, and reduce labor-intensive processes. Despite the proliferation of three-dimensional printing technologies in dentistry, the absence of well-established post-processing protocols has posed formidable challenges. This comprehensive review paper underscores the critical importance of precision in post-processing techniques for ensuring the acquisition of vital properties, encompassing mechanical strength, biocompatibility, dimensional accuracy, durability, stability, and aesthetic refinement in 3D-printed dental devices. Given that digital light processing (DLP) is the predominant 3D printing technology in dentistry, the main post-processing techniques and effects discussed in this review primarily apply to DLP printing. The four sequential stages of post-processing support removal, washing, secondary polymerization, and surface treatments are systematically navigated, with each phase requiring meticulous evaluation and parameter determination to attain optimal outcomes. From the careful selection of support removal tools to the consideration of solvent choice, washing methodology, and post-curing parameters, this review provides a comprehensive guide for practitioners and researchers. Additionally, the customization of post-processing approaches to suit the distinct characteristics of different resin materials is highlighted. A comprehensive understanding of post-processing techniques is offered, setting the stage for informed decision-making and guiding future research endeavors in the realm of dental additive manufacturing.

The Efficacy of Intense Pulsed Light and Laser Hair Removal in Hidradenitis Suppurativa Treatment.

Hidradenitis suppurativa (HS) is a multifactorial disease that presents with chronic cycles of inflammation, healing, and scarring and that elicits a profoundly negative impact on patient quality of life regarding self-image, fear of stigmatization, and social isolation. Patients commonly develop painful, odorous abscesses that evolve into draining sinus tracts and disfiguring scarring. While systemic medications and surgical therapies are often effective in reducing active lesion activity and inflammation, these therapies sometimes only provide modest success in the prevention of future recurrences and disease progression, warranting adjunctive therapies such as laser and light-based therapies.1 Herein, this systematic review has been conducted to assess the current level of evidence supporting intense pulsed light (IPL) and laser treatment for HS, with a focus on a decrease in the number of lesions with associated HS flares. GRADE assessments were performed using PubMed and Scopus. Of 428 studies identified, 10 studies (n= 235) evaluated IPL or laser hair removal treatment and their effectiveness in reducing HS flares. Significant reductions in the overall count of inflammatory lesions were observed in all studies, with percentages ranging from 50% to 75%, and in some cases, achieving complete resolution. However, durations of disease remission varied. These results provide a moderate level of evidence supporting the effectiveness of IPL and laser hair removal as adjunctive therapy in the treatment of HS; however, further long-term studies are required to provide future guidance on the most effective treatment duration and intervals for sustaining disease clearance. J Drugs Dermatol. 2024;23(11):926-930. doi:10.36849/JDD.8627.

Integrating electrochemical pretreatment with microalgae treatment for nitrogen and phosphorus removal and resource recovery from swine wastewater

This study integrates electrochemical pretreatment with microalgae (Scenedesmus obliquus) treatment to enhance nitrogen and phosphorus removal and resource recovery from swine wastewater. By optimizing electrochemical and microalgae treatment conditions, the dilution factor and the hydraulic retention time for microalgae treatment were reduced to 5 times and 7 days, respectively. Under the optimized operational conditions, removal efficiencies of total nitrogen and ammonia could reach over 89 %and 96 %,respectively, and the removal efficiency of total phosphorus was over 99 %. The study also found that aluminum was more suitable than iron for anode as it produced fewer residues. Additionally, the electrochemical pretreatment reduced Cu2+ and Zn2+ concentrations, mitigating negative impacts on microalgal growth. The microalgae biomass harvested from developed processes was rich in saturated fatty acids, which was desirable for biodiesel production. This approach addresses the challenges of nutrient removal for swine wastewater treatment with high quality biomass recovery.

Integrating Suspended Sludge and Fixed Film into a Biological Wastewater Treatment System to Enhance Nitrogen Removal

Integrated fixed-film activated sludge (IFAS) technology greatly enhances nitrogen removal effectiveness and treatment capacity in municipal wastewater treatment plants, addressing the issue of limited land availability. Hence, this method is appropriate for treating household wastewater from office buildings. The research was conducted at the wastewater treatment plant in an office building in Ho Chi Minh City, Vietnam. Experiments were conducted to ascertain the most favorable working conditions, including hydraulic retention time (HRT), alkalinity dosage, and dissolved oxygen (DO). According to the study, the IFAS system had the highest nitrogen removal effectiveness when operated at a hydraulic retention time (HRT) of 7 h, an alkalinity dose of 7.14 mgCaCO3/mgN-NH4+, and a dissolved oxygen (DO) value of 6 mg/L. The nitrification efficiency ranges from 89.2% to 98.8%. The N-NO3− concentration post-treatment is within the range of 27–45 mgN-NO3−/L, which is lower than the allowable discharge limit of 60 mg/L as per Vietnam’s wastewater discharge requirements. The research findings have enhanced the efficiency of the office building management process, thereby promoting the sustainable growth of society.

Facile Synthesis of Core-Shell Magnetic Iron Oxide@SiO2-NH2 Nanoparticles and Their Application in Rapid Boron Removal from Aqueous Solutions

In this study, amino-functionalized magnetic particles (iron oxide@SiO2-NH2) with core-shell structures were synthesized and evaluated for rapid boron removal from aqueous solutions. The results showed that the specific surface area of the iron oxide@SiO2-NH2 (131.24 m2⋅g−1) increased greatly compared to pure iron oxide (30.98 m2⋅g−1). The adsorption equilibrium was less than 2 h, with an adsorption capacity of 29.76 mg⋅g−1 at pH = 6 at 15 °C. The quasi-second-order kinetic model described the boron adsorption process well, and both the Langmuir and Freundlich models were suitable for characterizing the adsorption isotherms. The zeta potential and XPS analysis before and after adsorption revealed that the main adsorption mechanism was the hydrogen bonding formation between the terminal -NH2 groups of the adsorbent and the boric acid. In addition, the adsorbent still maintained a high adsorption performance after five adsorption–desorption cycles, which illustrated that the iron oxide@SiO2-NH2 may be a potential adsorbent for environmental boron removal treatment.

Electrolyzed water combined with ozone treatment for efficient removal of mancozeb residues from grapes.

Existing cleaning methods mainly focus on removing free-state pesticides. However, mancozeb can bind to the wax layer of grapes, forming bound-state residues that are difficult to remove. This study aims to develop an effective cleaning strategy to eliminate both free and bound mancozeb residues from grapes. Compared with the untreated mancozeb aqueous solution, the concentration of free mancozeb significantly decreased (p<0.05) after treatment with ozonated water (OW), electrolyzed water (EW), and their combination (OW+EW) for 60min. The combined treatment synergistically promoted mancozeb degradation, thus reducing its half-life to 38% and 75% of that observed when OW and EW were used alone, respectively. To investigate the effect of the waxy layer on mancozeb removal, oleanolic acid (OLA) was selected as a representative component. The binding effect of OLA limited the degradation of mancozeb in OW and EW, extending its half-life by 1.27 and 1.20 times, respectively. Density functional theory elucidated the mechanism by which the binding of OLA affects the degradation of mancozeb. Interestingly, the decomposition of mancozeb in OW + EW was almost unaffected by the introduction of OLA, indicating that the combined treatment could effectively remove bound-state mancozeb. The combined treatment was then successfully applied to remove mancozeb from grapes. After exposure to OW + EW for 10 min, the removal efficiency of mancozeb reached up to 80.61% with minimal risks of ethylene thiourea formation. There was no obvious change in the surface color of grapes after treatment. The findings provide valuable guidance for removing mancozeb from fresh fruits rich in waxy coatings.

Green Synthesis of Metal Nanoparticles with Borojó (Borojoa patinoi) Extracts and Their Application in As Removal in Water Matrix.

The predominant aim of the current research was to generate a proposal for the removal of arsenic, a highly toxic pollutant, encountered within the Papallacta Lagoon in Ecuador. The average concentrations of As yielded ranges between 18 to 652 μg/L, through the use of metallic nanoparticles. Sampling was performed in the lagoon with their respective geographic locations and "in situ" parameters. Nanoparticles of Mn3O4 NPs, Fe3O4 NPs, and CuO NPs were synthesized at a 0.5 M concentration, using the precipitation method, and borojó (Borojoa patinoi) extract was added as an anti-caking agent as well as antioxidant. The nanoparticles were characterized by visible spectrophotometry, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Raman spectroscopy. After arsenic removal treatment using nanoparticles, a randomized experimental design of different concentrations (5 mg/L, 10 mg/L, 25 mg/L, 50 mg/L, 100 mg/L, and 150 mg/L) was applied at laboratory level. The average diameter of Fe3O4NPs ranged from 9 nm to 36 nm, Mn3O4 NPs were 15-20 nm, and CuO NPs ranged from 25 nm to 30 nm. Arsenic removal percentages using Fe3O4 NPs with a concentration of 150 mg/L was 87%; with Mn3O4 NPs, the removal was 70% and CuO NPs of about 63.5%. Finally, these nanoparticles could be used in a water treatment plant for the Papallacta Lagoon.

Assessment of urbanization impacts in Tegucigalpa urban greenness via normalized difference vegetation index

Urban vegetation is essential to develop sustainable, habitable, and healthy cities. Urbanization in large cities may be detrimental to urban vegetation when urban planning is scarce. Tegucigalpa, Honduras's capital city, had an atypical 8-year period of intensive urbanization, which may have modified urban vegetation. Excessive tree removal and reduced urban greenness reports became abundant in local media. This paper aimed to determine if urbanization indeed modified Tegucigalpa's urban greenness to a detrimental level. A Landsat-8 imagery survey was conducted to assess Tegucigalpa's urban vegetation dynamics via the normalized difference vegetation index (NDVI) for the 2013–2021 dry and rainy seasons. The results revealed a stable trend for the dry seasons NDVI remaining in constant proximity to 0.11 while increasing steadily to around 0.17 during the rainy seasons due to precipitation watering vegetation. Negligible fluctuations (<0.1) occurred throughout the study period, suggesting urbanization most likely did not shrink urban vegetation to the extreme extent stated by Honduran media. The NDVI provided a scientific basis for assessing Tegucigalpa's vegetation changes, preventing potential environmental conflicts. Although most researchers have reported that urbanization decreases NDVI in large cities, others found that urbanization does not always produce vegetation degradation and suggested that climatic variables are significant factors determining vegetation growth. Nevertheless, the steadily low NDVI in Tegucigalpa suggests the absence of sustainable urban planning to increase urban vegetation. Urban trees are central to sustainable urban planning; therefore, afforestation policies should be considered by Tegucigalpa's government and policymakers.

Evaluation of Axillae Skin Thickness by High-Frequency Ultrasound.

High-frequency ultrasound has been utilized in dermatology to visualize superficial cutaneous structures. Axillae are often target of treatments for hair removal, for spot clearing, and for skin conditions such as hyperhidrosis, bromhidrosis, and hidradenitis. Detailed knowledge of armpit thickness can help improve existing therapies and increase their effectiveness. To describe the mean skin thickness of axillae, by further investigating possible correlations with variations in age, sex, and body mass index (BMI). Axillae were divided into 5 quadrants, 1 central and 4 peripherals. Skin has been assessed by ultrasonography, measuring the distance from epidermis surface to dermal depth, in millimeters, for each of the regions. Thirty healthy patients participated, most of them were female (n = 22; 73%), mean age 50 years (26-70 years). Most patients have maximum thickness in the center of axillae (87%). Average skin thickness in the central region was 3.1 ± 0.4 mm. There was significant difference between axillary thickness in central and peripheral regions (p < .05). On the periphery, the mean thickness was smaller (1.8 mm) without significant variation between the squares. There was no significant variation of skin thickness by sex, age, and BMI. This study shows a difference between thickness of axillae in the central region and in its periphery.

Management of Huanglongbing of Citrus: Lessons from São Paulo and Florida.

São Paulo, Brazil, and Florida, USA, were the two major orange production areas in the world until Huanglongbing (HLB) was discovered in São Paulo in 2004 and Florida in 2005. In the absence of resistant citrus varieties, HLB is the most destructive citrus disease known because of the lack of effective tools to reduce spread of the vector, Diaphorina citri (Asian citrus psyllid), and transmission of the associated pathogen, Candidatus Liberibacter asiaticus. In both countries, a three-pronged management approach was recommended and begun: planting only disease-free nursery trees, effective psyllid control, and removal of all symptomatic trees. In Brazil, these management procedures were continued and improved and resulted in relatively little overall loss of production. In contrast, in Florida the citrus industry has been devastated with annual production reduced by approximately 80%. This review compares and contrasts various cultural and pest management strategies that have been used to reduce infection by the pathogen and increase tolerance of HLB in the main orange-growing regions in the world.

Cover crop grazing length impacts on soil health and crop productivity in US Coastal Plain soils

AbstractIntroducing integrated crop‐livestock systems into row crop production promotes income diversification and potential soil health benefits through cover crop grazing on degraded soils of the southeastern United States, but effects of these practices on crop yields and soil health in Coastal Plain soils are not well established. A 4‐year study was performed to evaluate the effects of grazing a multi‐species winter cover crop on soil health and crop yields under mid‐February, mid‐March, and mid‐April cattle removal dates and a non‐grazed control within an annual cotton (Gossypium hirsutum L.) and peanut crop rotation (Arachis hypogaea L.). Chemical soil health indicators (soil organic carbon and permanganate oxidizable carbon), physical soil health indicators (water‐stable aggregates and penetration resistance), biological soil health indicators (microbial biomass carbon, soil respiration, and arbuscular mycorrhizal fungi colonization), crop yield, and cover crop biomass were evaluated. Cover crop biomass at termination was reduced by 3660, 5250, and 5610 kg ha−1 for the mid‐February, mid‐March, and mid‐April cattle removal treatments compared to the non‐grazed control. No grazing treatment effects were observed for biological soil properties. Soil organic carbon was higher in the non‐grazed treatment than the mid‐April grazing treatment across 0‐ to 30‐cm depth. Penetration resistance across 0‐ to 50‐cm depth and water‐stable aggregates at the 0‐ to 30‐cm depth were both negatively impacted by increased grazing period lengths. Results from this study suggest that longer cover crop grazing periods have little effect on biological and chemical soil health indicators in the short term but can negatively impact some physical soil health indicators.

Long‐term tillage and residue removal effects on soil carbon, nitrogen, and grain yield in irrigated corn

AbstractCorn (Zea mays L.) stover demand as a forage or for an emerging bioeconomy has increased the importance of determining the long‐term effects of stover removal on grain yield and soil properties. Study objectives were to evaluate grain yield, soil organic carbon (SOC), and total soil N (0–150 cm) in a 20‐year, irrigated, continuous corn study, located in eastern Nebraska, under conventional tillage (CT) and no‐till (NT) with variable corn stover removal rates (none, medium, and high). After 20 years, grain yield was up to 6.0% greater under NT with stover removal compared with NT and no stover removal, while yield was similar for CT in all stover removal treatments. Grain yield was similar between NT with stover removal and CT in all stover removal treatments. High stover removal rates resulted in greater SOC loss at the surface soil layers (0–15 cm and 0–30 cm) after 20 years compared with no or medium stover removal. Corn stover retention under NT resulted in the same cumulative SOC stock loss as CT or stover removal. All management practices resulted in cumulative (0–120 cm) SOC stock loss (8% decrease) that occurred in the last 10 years of the study. Total soil nitrogen stocks were maintained or increased after 20 years at the surface soil layers (0–15 cm and 0–30 cm) and were similar between NT and CT. In an irrigated continuous corn system, neither NT nor stover retention was able to maintain cumulative SOC stocks over time.

52183 What is the most effective treatment for tattoo removal?: Six cases, three different ways

52183 What is the most effective treatment for tattoo removal?: Six cases, three different ways

A cross-sectional study on dental anxiety and state anxiety related to removal of fixed partial dentures.

This study aimed to evaluate the effect of the clinical removal of fixed partial dentures on oral health-related quality of life and the anxiety values of individuals and to determine the clinical factors of high anxiety levels. In total, 300 participants were included in the study. Six different reasons for the clinical removal of fixed partial dentures (oral examination, denture renewal, endodontic treatment, tooth extraction, periodontal treatment, and composite filling restoration) were defined. The United Kingdom Oral Health-Related Quality-of-Life Measure (OHRQoL-UK), the Modified Dental Anxiety Scale (MDAS), and the Spielberger State-Trait Anxiety Inventory- State (STAI-S) and Trait (STAI-T) were answered. The reason groups were compared using one-way analyses of variance. Binary logistic regression analyses were performed to evaluate the risk factors for high anxiety. There was no significant difference in OHRQoL-UK scores (P &#61; .279) among the reason groups, but there were significant differences in MDAS, STAI-S, and STAI-T scores (P &#61; .004, P .001, P &#61; .018, respectively) among the reason groups. Endodontic treatment, tooth extraction, and sex were determined to be risk factors, considering the anxiety scales. Females are 2.2 times more likely to have trait anxiety than men. Although the effect of the reason for the clinical removal of fixed partial dentures on oral health-related quality of life was similar among the groups, it is concluded that endodontic treatment and tooth extraction reasons for the clinical removal of fixed partial dentures could be risk factors for high anxiety regardless of fixed partial denture usage time.

Modeling the Transmission Dynamics and Optimal Control Strategy for Huanglongbing

Huanglongbing (HLB), also known as citrus greening disease, represents a severe and imminent threat to the global citrus industry. With no complete cure currently available, effective control strategies are crucial. This article presents a transmission model of HLB, both with and without nutrient injection, to explore methods for controlling disease spread. By calculating the basic reproduction number (R0) and analyzing threshold dynamics, we demonstrate that the system remains globally stable when R0&lt;1, but persists when R0&gt;1. Sensitivity analyses reveal factors that significantly impact HLB spread on both global and local scales. We also propose a comprehensive optimal control model using the pontryagin minimum principle and validate its feasibility through numerical simulations. Results show that while removing infected trees and spraying insecticides can significantly reduce disease spread, a combination of measures, including the production of disease-free budwood and nursery trees, nutrient solution injection, removal of infected trees, and insecticide application, provides superior control and meets the desired control targets. These findings offer valuable insights for policymakers in understanding and managing HLB outbreaks.

Efficacy and safety of triple diode laser in hair growth reduction

ABSTRACT Background &amp; Objective: Laser treatment for hair removal is a very common procedure in dermatology. Ruby, diode, alexandrite, Nd yag, and intense pulse light are frequently used for hair reduction. For more effective results a combination of wavelengths is used. The purpose of this study is to determine the efficacy and safety of triple diode lasers in hair growth reduction. Methodology: This interventional longitudinal study comprises of total 82 patients using a non-probability convenience sampling technique, the mean age of the patients was 28.73, the age range was between 17 to 56 years, and all patients in this study were female of skin phenotype between III to V. Each session was done one month apart for four months, and hair growth reduction was assessed by using GAIS (Global Aesthetic Improvement Scale Assessment) score by two independent dermatologists in 4th session. Results: Hair growth reduction was observed in all the enrolled patients from the first session. Out of 82 patients, 63.4% of patients are of skin phenotype IV, 23.2% patients are of skin phenotype III whereas 13.4% are skin phenotype V. After four sessions 41 patients (50%) showed excellent results, and 41 patients (50%) showed good results. None of these patients experienced any long-term side effects. Conclusion: Triple diode laser is a safe and effective modality in hair growth reduction at all body sites in skin phenotype III- V with minimal side effects.

Assessment of environmental sustainability of drinking water treatments for arsenic removal

To date, few studies that developed a complete Life Cycle Assessment (LCA) are available in literature, but they are limited to non-conventional processes and did not take into consideration the entire drinking water treatment plant (DWTP). Moreover, few data of the environmental impact are currently available for some of the most widely applied technologies such as biological filtration and coagulation. This study aims to overcome this research gap carrying out a LCA in order to identify (i) what is the most impactful process, and (ii) what possible solutions for mitigating the impact can be proposed. Focusing on the treatment for arsenic removal, the results showed that coagulation was the most impactful process mainly due to the electricity consumption while, looking at the entire DWTP, disinfection prevails. In view of potential up-grade, the use of green energy can effectively increase the sustainability.

Grassland restoration on linear landscape elements – comparing the effects of topsoil removal and topsoil transfer

Artificial linear landscape elements, including roads, pipelines, and drainage channels, are main sources of global habitat fragmentation. Restoration of natural habitats on unused linear landscape elements can increase habitat quality and connectivity without interfering with agricultural or industrial development. Despite that topsoil removal and transfer are widely applied methods in restoration projects, up to our knowledge these were previously not compared in the same study system. To address this knowledge gap, we compared spontaneous vegetation recovery after the elimination of positive (embankments) and negative landscape scars (drainage channels) in lowland alkaline landscapes in South Hungary. The novelty of our study is that we compared the fine-scale and landscape-scale results of both methods. At the fine scale, we monitored the spontaneous vegetation development on the created open surfaces in the first, second and fourth year after restoration in 160 permanent plots per year. For characterizing the habitat changes on the landscape scale, we prepared habitat maps and assigned naturalness scores to each patch before and after the restoration activities. Both restoration methods resulted in a rapid vegetation recovery at the fine scale, progressing toward the reference state. In the topsoil removal treatment, a large part of the soil seed bank was removed; therefore, the colonization of the bare surface was a slower process. Seeds of halophytes, including the endemic and protected Suaeda pannonica, were probably present in the deeper soil layers, and these species became established in the restored surfaces, despite being absent in the surrounding vegetation. For restoring vegetation cover, topsoil transfer was a more rapid option; however, vegetation closure and competition by generalist species and weeds hampered the establishment of target species. The removal of the landscape scars by both methods made the sites accessible for grazing. At the landscape scale, the two methods had different effects: there was a slight increase in the habitat naturalness in the topsoil removal site, and a slight decrease in the topsoil transfer site because of weed encroachment. Spreading an upper layer of nutrient-poor soil with low amounts of weed seeds, direct propagule transfer, and targeted grazing regimes could enhance restoration success.

Despite regional variation, Gymnorhinus cyanocephalus (Pinyon Jay) densities generally increase with local pinyon–juniper cover and heterogeneous ground cover

Abstract Traditionally, local-scale habitat-relationship models are developed over small spatial extents, limiting model transferability and inference outside the study area. Thus, habitat managers frequently lack fine-scale information regarding the influence of vegetation composition and structure on site suitability or species abundance. Gymnorhinus cyanocephalus (Pinyon Jay) represents one declining species for which managers have limited information regarding the influence that vegetation composition and structure have on abundance at broad scales. To address this need, we developed a hierarchical Bayesian abundance model using summertime bird and vegetation data collected under the Integrated Monitoring in Bird Conservation Regions program to explain jay abundance as a function of local conditions. Our G. cyanocephalus abundance model allowed abundance relationships with pinyon pine (Pinus edulis and P. monophylla) and juniper (Juniperus spp.) to vary by ecoregion, thereby accounting for potential regional differences in habitat associations. We found G. cyanocephalus abundance was generally positively associated with pinyon pine and juniper cover; however, habitat relationships varied by ecoregion. Additionally, we found positive associations between jay abundance and grass cover, sagebrush cover, and percent bare ground. Our results agree with prior research suggesting mechanical removal of pinyon pine and juniper trees for sagebrush restoration or fuel treatments may negatively affect G. cyanocephalus. Managers wishing to reduce pinyon and juniper tree cover without negatively affecting G. cyanocephalus may benefit from targeting sites where both large-scale distribution models and our local habitat relationships suggest G. cyanocephalus are likely to occur in low numbers. Additionally, our modeled relationships indicate restoration that increases grass cover, sagebrush cover, and bare ground, while maintaining pinyon and (or) juniper cover, may lead to increased local densities of G. cyanocephalus.

Spatial scale of stand-replacing forest disturbance influences the amplitude of snowshoe hare population fluctuations in boreal forests of northwest Canada

The natural disturbance model for ecosystem management of timber harvesting promotes the emulation of natural disturbance regimes in the patterns of tree removal. Wildfire is a prominent natural disturbance in boreal forests of western Canada, frequently removing most of the tree canopy from patches of 500–10,000 ha in stand-replacing events. However, fire suppression, coupled with a spatial pattern of timber harvesting dominated by small patch cuts of 10–160 ha, have changed the spatial scale of younger stands away from scales within which boreal organisms evolved. In two regions (Sub-Boreal Spruce biogeoclimatic zone of central British Columbia and Liard Basin of southeast Yukon), we tested the hypothesis that different spatial scales of stand-replacing forest disturbance (wildfire and timber harvesting) result in different amplitudes of change in abundance of snowshoe hare, a keystone boreal forest mammal for which mid-seral stand conditions provide optimal habitat. Landscapes with large patches (>2000 ha) of mid-seral forest following stand-replacing disturbance supported consistently and often significantly more hares, with wider amplitude in cyclic fluctuation, than small patches (20–200 ha) of mid-seral habitat and than mature forest landscapes. Densities of hares high enough to support reproduction by Canada lynx (a specialist hare predator) only occurred in landscapes disturbed at the scale of a moderate to large-sized wildfire (1000 – 10,000 ha). Landscapes unaffected by stand-replacing disturbance for at least 80 years (i.e. mature forests) supported very few hares and without cyclic fluctuations. We recommend that the recent pattern of cutting dominated by small patches (20–200 ha) be shifted to include many larger patches (2000–5000 ha). This can happen with incremental, contiguous patch cutting over a period of years short enough that the completed patch will supply high quality, mid-seral habitat for at least the period of one hare cycle (10 y). In designing relatively large patches, mature green tree retention would be desirable for various values, but would be best as small stands of mature forest dispersed within large patch cuts, similar to the legacy of fire. Silviculture (reforestation and stand tending) should create and sustain a mix of conifer and deciduous regeneration in the mid-seral stands. Emulating spatial patterns of stand-replacing natural disturbance appears necessary to sustain snowshoe hare cycles when most fires are suppressed in intensively managed western Canadian boreal forests.